1. Technical Field
The present disclosure relates to a compressor housing for a supercharger.
2. Description of Related Art
Compressors (compression machines) used in superchargers, such as turbochargers, of automobiles have compressor housings. Compressor housings are configured to house impellers therein. Each compressor housing has an intake port, a scroll chamber, and a shroud surface. The intake port is configured to take in air toward the impeller. The scroll chamber is formed outward of a circumference of the impeller in a circumferential direction. The scroll chamber introduces the air discharged from the impeller. The shroud surface is so disposed as to face the impeller.
In the above configured compressor, a gap between impeller blades and the shroud surface of the compressor housing is set to be as small as possible, thereby enhancing compression efficiency of the compressor. However, if the gap is too small, damages might be caused to the impeller. Such damages might be caused, for example, if the impeller blades come into contact with the shroud surface of the compressor housing due to vibrations, run-out of a rotational axis of the impeller, or the like.
Japanese Patent Application Publication No. 9-170442 discloses a structure of providing a sliding member made of a softer resin or the like than an impeller blade to a portion where a shroud surface of a compressor housing is formed. According to this, even if the impeller blades come into contact with the shroud surface of the compressor housing due to vibrations, run-out of the impeller rotation axis, or the like, only the sliding member provided to the portion where the shroud surface is formed becomes cut. Hence, no damage is caused to the impeller. A gap between the impeller blades and the shroud surface of the compressor housing is maintained to be small.